U.S. Pat. No. 4,476,184, incorporated by reference, discloses thermoplastic polysulfone oligomers having dimethyloxynadic (DONA) crosslinkable end caps to impart solvent-resistance to the cured resins. Similar oligomers having difunctional nadic, maleic, and phenylacetylenic end caps are disclosed in U.S. Pat. No. 4,536,559, which also is incorporated by reference.